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Title:

Left-Turn Crash Injury Severity Analyses Using Partial Proportional Odds Models: Significant Factors and Varying Effects

Accession Number:

01103649

Record Type:

Component

Availability:

Transportation Research Board Business Office

500 Fifth Street, NW
Washington, DC 20001 United States

Abstract:

Statistics show that left-turning traffic colliding with opposing through traffic and with near-side through traffic are the two most frequently occurring conflicting patterns among left-turn crashes (Patterns 5 and 8 in the paper, respectively), and they are prone to be severe. The purpose of this study is to deeply examine left-turn crash injury severity and therefore to develop efficient countermeasure to reduce severe crashes. Ordered probability models with either logit or probit function is commonly applied in crash injury severity analyses; however, its critical assumption that the slope coefficients do not vary over different alternatives except the cut-off points is usually too restrictive. Partial proportional odds models are generalizations of ordered probability models, for which some of the beta coefficients can differ across alternatives. They were applied to investigate Patterns 5 and 8, and the total left-turn crash injury, and results show that partial proportional odds models consistently perform better than ordered probability models. Focusing on specific conflicting patterns, locating crashes to the exact crash sites and relating approach variables to crash injury in the analysis enable the researchers to deeply investigate how these variables affect injury severity. For example, opposing through traffic and near-side crossing through traffic in the crash hour are significant for Patterns 5 and 8 crash injury, respectively. Protected left-turn phasing is significantly correlated with Pattern 5 crash injury. Many other variables in driver attributes, vehicular characteristics, roadway geometry design, environmental factors, and crash characteristics are identified.

Monograph Accession #:

01084478

Report/Paper Numbers:

08-0297

Language:

English

Corporate Authors:

Transportation Research Board

500 Fifth Street, NW
Washington, DC 20001 United States

Authors:

Wang, Xuesong
Abdel-Aty, Mohamed A

Pagination:

19p

Publication Date:

2008

Conference:

Transportation Research Board 87th Annual Meeting

Location: Washington DC, United States
Date: 2008-1-13 to 2008-1-17
Sponsors: Transportation Research Board

Media Type:

DVD

Features:

Figures (2) ; References (25) ; Tables (6)

Subject Areas:

Data and Information Technology; Highways; Operations and Traffic Management; Safety and Human Factors; I81: Accident Statistics; I82: Accidents and Transport Infrastructure; I85: Safety Devices used in Transport Infrastructure

Source Data:

Transportation Research Board Annual Meeting 2008 Paper #08-0297

Files:

TRIS, TRB

Created Date:

Jan 29 2008 2:39PM